1. Field of the Invention
This invention generally relates to an apparatus for recording a color video signal and in particular is directed to such a recording apparatus in which chrominance component signals are time-compressed and sequentially recorded on a track separate from a luminance component track.
2. Description of the Prior Art
In the art, there has been known a recording method for a color video signal, in which a luminance signal and a pair of chrominance component signals included in a color video signal are separated and then sequentially recorded on separate tracks. In this case, a pair of chrominance component signals such as a pair of color difference signals (R-Y) and (B-Y) are respectively compressed in timebase to the half (1/2) thereof, arranged sequentially and alternately with respect to each and then recorded on one track.
A reference clock signal employed in a timebase compressor which compresses in timebase the pair of color difference signals (R-Y) and (B-Y) is generally related to a color subcarrier signal. If the frequency of the reference clock signal is the frequency mfsc (m is an integer) which is related to a color subcarrier frequency fsc, a problem occurs in the circuit configuration of the recording apparatus and so on.
When the reference clock signal is formed on the basis of the color subcarrier frequency fsc, the timebase compressor must be constructed in accordance with respective television standard systems. In other words, as will be apparent, the NTSC (national television systems committee) system and the CCIR (international radio consultative committee) system each have different color subcarrier frequencies fsc depending on each television standard system. Accordingly, if the reference clock signal is formed on the basis of such color subcarrier frequency fsc and is used in driving the timebase compressor, the compressing ratio is different in each television standard system and a desired compressing ratio can not be obtained. Therefore, depending on the television standard system, the circuit configuration and constant or the like must be changed greatly. Thus, the timebase compressor can not be used common to different television standard systems, which fact then causes a serious disadvantage in coping with different television standard systems.
Moreover, since the color subcarrier frequency fsc is selected to be an odd multiple of half of the horizontal frequency f.sub.H, the timing of the clock signal is displaced by half the amount of the clock signal at every horizontal line. Thus, the position of a reference pulse inserted into the compressed color difference signals and used for matching the timebase of the luminance signal upon reproducing must be shifted at every line, thus making the configuration of a reference pulse generating circuit complicated. PG,4